1. Field of the Invention
This invention relates to an optical disk apparatus for recording data to be recorded such as input video data on an optical disk and in particular to record processing of data to be recorded.
2. Description of the Related Art
To record data on an optical disk in an optical disk apparatus capable of recording data on an optical disk such as a DVD, the record data needs to be recorded continuously at constant speed. Thus, an optical disk apparatus in a related art is provided with buffer memory for temporarily storing encoded data before being recorded to maintain the data record continuity. At the time, if data is not stored in the buffer memory, data record on an optical disk is forcibly interrupted and the data record continuity cannot be maintained and when the buffer memory fills with data, encode processing must be interrupted at the point in time. Thus, the amount of the data stored in the buffer memory needs to be monitored.
Proposed as a unit for monitoring such data stored in buffer memory is a unit for interrupting data record on an optical disk if a buffer under run occurs, namely, if the data stored in the buffer memory becomes a predetermined amount or less and restarting data record while maintaining continuity if data is stored. (For example, refer to JP-A-2002-132452.)
Proposed as another unit for monitoring such data stored in buffer memory is a unit provided with a timer for monitoring the amount of the data stored in the buffer memory every predetermined time and temporarily storing data responsive to the free storage space in the buffer memory. (For example, refer to JP-A-2001-290605.)
However, in the optical disk apparatus described in JP-A-2002-132452, if the data stored in the buffer memory becomes the predetermined amount or less while data is being stored, the data record is interrupted and therefore it is impossible to continuously and stably record data on the optical disk. In the optical disk apparatus described in JP-A-2001-290605, the timer circuit is provided for monitoring the buffer memory every predetermined time and the monitor time interval must be set properly and optimum control is hard to perform. The timer circuit is required aside from the circuit configuration involved in data record, the circuit configuration is upsized as compared with the case where the circuit configuration involved in data record is included, and control becomes complicated accordingly.